President Donald Trump announced on Thursday his decision to withdraw the United States from the Paris climate accord, the landmark 2016 agreement that held support from a majority of Americans in every state.

Later on Thursday, another politically active billionaire, Michael Bloomberg, stepped in to partially alleviate the impact of the policy shift. Through his foundation, Bloomberg Philanthropies, he pledged up to $15 million to the United Nations Framework Convention on Climate Change, which will likely lose a comparable amount in funding from the U.S. as a result of the American withdrawal. The UNFCCC works principally to stabilize greenhouse gas concentrations in the atmosphere.

In a press release distributed on Thursday evening, Bloomberg commented, “Americans are not walking away from the Paris Climate Agreement. Just the opposite—we are forging ahead.”

Bloomberg, 75, currently serves as the UN Secretary-General’s Special Envoy for Cities and Climate Change. A former registered Republican who later served as mayor of New York City as an independent, he has given millions of dollars to liberal causes like gun control and Planned Parenthood. He endorsed Democratic nominee Hillary Clinton in the 2016 presidential race.

The announced donation will hardly dent the coffers of Bloomberg Philanthropies, which distributed more than $500 million in 2016 alone. Michael Bloomberg is worth $50.2 billion, according to Forbes' real-time rankings of the world’s billionaires. Much of that wealth lies in his ownership of financial data and news provider Bloomberg LP. He is currently the ninth richest person on the planet, according Forbes.

The ultimate fiscal effect of climate change is unknown, though a 2016 study from the London School of Economics noted that $2.5 trillion in global assets will be at risk if the “global mean surface temperature rises by 4.5 degrees Fahrenheit above its pre-industrial level by 2100.”

In the context of such numbers, Bloomberg’s $15 million gift may ultimately prove negligible. But as a political statement following President Trump's decision, his donation holds power.